A PDF owner password is a password used to set certain document restrictions (more on those below) in PDF files.
In Adobe Acrobat, this is called the change permissions password. Depending on the PDF reader or writer you're using, you may also see the PDF owner password referred to as the PDF permissions password, restriction password, or master password.
What Does a PDF Owner Password Do?
As of the latest PDF version, document restrictions put in place with an owner password can include the following:
- Printing
- Changing the document
- Document assembly
- Content copying
- Content copying for accessibility
- Page and graphics extraction
- Commenting
- Filling of form fields
- Signing
- Creation of template pages
Depending on the PDF writer you're using, a few of which are listed in the next section below, you should be able to allow some restrictions while blocking others. For example, you could disable copying of text and images but enable printing, which is helpful if you want to distribute a PDF but want to discourage duplicating parts of your proprietary work.
It doesn't matter if only some restrictions are in place or if all of them are, you still have to provide to the PDF reader the change permissions password before you're given full, unrestricted access to the document.
How to Set a PDF Owner Password
There are plenty of free programs that support PDF restrictions via configuring a PDF owner password.
A few examples include a PDF maker like PDF24 Creator, and other related tools like PDFill Free PDF Tools (via the encrypt/decrypt option), PrimoPDF, and Nitro Pro.
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Each PDF writer has a different process for doing this in their respective programs but since the ability is provided via the PDF standard, they're all going to be pretty similar in most ways.
How Do I Stop Someone From Opening a PDF?
In addition to using a PDF owner password to restrict what can be done to an open PDF, you can even prevent someone from opening the PDF at all. That's right—you can actually lock it down so tight that a password is needed to see any of the contents at all.
Because an owner password doesn't restrict the opening of the document, you must use a PDF user password to provide "document open" security.
Some of the programs we've already talked about will also let you enable a user password to secure a PDF from being opened.